texture disappears with gluSphere and glutPostRedisplay - c++

Question

I'm just starting with opengl. This is my first project, in fact.
I want to map some texture to a quadrilateral in the background and want to draw a sphere using gluSphere in the front and I want to animate this. So, I map the texture first, then draw the sphere in the display function and then call glutPostRedisplay. It does show the texture and the sphere correctly when display is first called. But, as soon as glutPostRedisplay is called, the texture disappears and only the sphere is drawn. I have given my code below. I apologize for using any bad opengl practices.
void display() {
glClear(GL_COLOR_BUFFER_BIT);
drawTex();
glPushMatrix();
glTranslatef(SIZE/2, SIZE/2, 0);
glutSolidSphere(15.0, 20, 20);
glPopMatrix();
glutSwapBuffers();
glutPostRedisplay();
}
void LoadTextureRAW( const char * filename, int wrap ) {
GLuint texture;
int width, height;
unsigned char * data;
FILE * file;
// open texture data
file = fopen( filename, "rb" );
if ( file == NULL ) {
return;
}
// allocate buffer
width = 1073;
height = 918;
data = (unsigned char *)malloc( width * height * 3 );
// read texture data
fclose( file );
// select our current texture
glBindTexture( GL_TEXTURE_2D, 1 );
// select modulate to mix texture with color for shading
glTexEnvf( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE );
// when texture area is small, bilinear filter the closest mipmap
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST );
// when texture area is large, bilinear filter the first mipmap
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
// if wrap is true, the texture wraps over at the edges (repeat)
// ... false, the texture ends at the edges (clamp)
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, wrap ? GL_REPEAT : GL_CLAMP );
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, wrap ? GL_REPEAT : GL_CLAMP );
// build our texture mipmaps
gluBuild2DMipmaps( GL_TEXTURE_2D, 3, width, height,
GL_RGB, GL_UNSIGNED_BYTE, data );
// free buffer
free( data );
}
void drawTex() {
glBegin(GL_QUADS);
glTexCoord2d(0.0,0.0);
glVertex3d(0.0,SIZE/2, -SIZE);
glTexCoord2d(1.0,0.0);
glVertex3d(SIZE, SIZE/2, -SIZE);
glTexCoord2d(1.0,1.0);
glVertex3d(SIZE, SIZE/2, SIZE);
glTexCoord2d(0.0,1.0);
glVertex3d(0.0, SIZE/2, SIZE);
glEnd();
glFlush();
}
void map() {
glClearColor(1.0, 1.0, 1.0, 1.0);
glClear(GL_COLOR_BUFFER_BIT);
glEnable( GL_TEXTURE_2D );
LoadTextureRAW("background.bmp", true);
glBindTexture( GL_TEXTURE_2D, 1 );
drawTex();
}
void init() {
glClearColor(1, 1, 1, 1);
glClearDepth( SIZE );
glOrtho(0, SIZE, 0, SIZE, -SIZE, SIZE);
GLfloat mat_ambient[] = { 1.0, 1.0, 1.0, 1.0 };
GLfloat mat_specular[] = { 1.0, 1.0, 1.0, 1.0 };
GLfloat mat_shininess[] = { 50.0 };
GLfloat light_position[] = { SIZE/2, 0, 1.0, 0.0 };
GLfloat model_ambient[] = { 0.5, 0.5, 0.5, 1.0 };
glClearColor(1.0, 1.0, 1.0, 1.0);
glMaterialfv(GL_FRONT, GL_AMBIENT, mat_ambient);
glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess);
glLightfv(GL_LIGHT0, GL_POSITION, light_position);
glLightModelfv(GL_LIGHT_MODEL_AMBIENT, model_ambient);
//glColor3f(0,0,0);
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glRotatef(-40, 1, 0, 0);
glRotatef(-40, 0, 1, 0);
map();
}
Any help would be really appreciated.

Answer 1

A few notes: In the fixed function pipleine the light position must be set, after the view transformation (=camera) has been applied to the modelview matrix. In fact the whole code in init() actually belongs in the display function.
glClearDepth should be set to 1 unless you know, what you're doing (the clear depth works in NDC space and as a OpenGL beginner this is something "too advanced" for a starting. Just set it to 1 and be happy.
The map() function makes no sense. Textures are initialized one time and then only bound before rendering textured geometry.
Last but not least glutSolidSphere doesn't generate proper texture coordinates. But you need to give OpenGL texture coordinates. My suggestion: Ditch glutSolidSphere and do the geometry yourself. Like this: https://stackoverflow.com/a/5989676/524368